Over the past two decades, global production of soybean has more than doubled. Both supply and demand factors have dramatically increased the area of agricultural land utilized for the production of the oilseed grain; the American Soybean Association estimates that around 83.2mt (million metric tonnes) were produced globally in 2011, amounting to 56% of world oilseed production. While production levels have increased across many markets, there remain significant asymmetries between supply and demand for soybean products, with production mostly concentrated in North and South Americas, but demand concentrated, and growing fastest, in China and the world’s developing economies. This necessarily means that large quantities of soybean, in multiple forms, pass through bulk ports around the world. Buttimer Bulk Engineering has designed a number of port and logistics facilities with mechanical handling systems for soybean meal, through which the company has built up significant knowledge of the principals and pragmatics of handling a unique, and sometimes difficult, bulk product.
The soybean crop is a legume; part of the reason for its remarkable growth in demand is due to its very high protein content and range of amino acids. About 85% of soybean crop produced will be crushed to produce edible oil and soybean meal, with the remainder used in its bean form as seeds, and food, primarily in China. The edible oil is used in a variety of food production contexts, adding protein or used as an emulsifier, it is also — and increasingly — being used in the production of biodiesel and ethanol. Soybean meal, the other by-product of the crushing process, is used in animal feeds. Changes in consumption and agricultural practices in China and the developing world — resulting in a large increase in beef production — are some of the main drivers of the growth in demand for soybean meal exported from North America, Brazil, Argentina and Paraguay, to Eastern Europe and Asia. In terms of the financial value of soybean products traded internationally, it is estimated that 50% is in the raw bean form, another 34% is soybean meal with the remainder being edible oil and a very small amount of finished soya products, such as tofu. International trade is further classified into GM (genetically modified) and non-GM soybean crops. A significant portion of the increase in global yield of soybean grains has been due to widespread use of pesticide resistant genetically modified crop varieties; these however are not accepted in some markets, notably the EU, and so further speciality and ‘organic’ varieties are produced and traded for specific markets.
HANDLING SOYBEAN MEAL
At Buttimer, the continued growth of bulk trade in soybean products has been seen as an opportunity to demonstrate strong port design and process engineering capability: understanding the behaviour of the bulk product and designing appropriate and efficient mechanical handling systems to manage its characteristics. In its unprocessed bean form, soya is relatively free flowing and can be handled like other loose bulk products such as maize (corn), or other grains, provided that the system includes no high drops of the product, keeping splitting and breakage of the seeds to a bare minimum. Like most grains, monitoring temperature and moisture levels to identify mould damage or insect activity should help maximize storage life and pre-empt deterioration. The handling of the soybean meal however is an altogether trickier, stickier problem; it is a poor- flowing bulk product and a mildly abrasive one, so the handling of soybean meal requires tailored process engineering with a strong focus on the safety of dust levels and the optimization of equipment lifecycles.
“The first and most important difference between designing handling systems for soybean meal and for other grains, is the level of dust, and the flammability of the dust, that you have to expect,” explains Mateusz Olejniczak, an engineer and project manager who has been responsible for a number of Buttimer’s soybean handling projects at ports and other facilities “while dust control is always important in grain handling systems, dust from soybean meal is particularly flammable, and there’s lots of it!” Buttimer assigns ATEX fire safety codes both internal and external to all relevant equipment, including investigation of the ignition point. It fits equipment with special spark prevention features such as plastic casings on bucket elevators, anti-static rubber on drums, rollers and other high friction points, as well as using anti-static belts on all conveying equipment. Anti-explosion precautions are essential design features of soybean handling plants, both for the protection and longevity of the mechanical handling equipment and the safety of any onsite staff. Assigning ATEX ratings, predicting dust levels in and around equipment, identifying transfer points and potential fire hazards are integral to Buttimer’s process engineering design, when dealing with a product like soybean meal the system needs to be tailored to the product’s characteristics, ‘off-the-shelf ’ handling solutions will be ineffective and often unsafe.
Soybean meal has an average density of 0.6 n/m3, substantially less than regular grain products which are around 0.75Tn/m3. It also has higher moisture and oil content and is less free-flowing than most grain products, requiring higher angles of conveyors and chutes to optimize flow. Free-flowing grains will usually travel easily at an angle of 40° to 45°, whereas soybean meal needs a slope of minimum 55° to ensure flow. The product’s poor flow, its ‘stickiness’ and tendency for compaction have a number of consequences for the layout and design of the handling system; for example, measures need to be taken to prevent the build-up of product at transfer points or in gaps along the process. Olejniczak describes the “need to prevent ‘dead-zones’ in your system — where some the product stops moving for a period of time.” Soybean meal that is left sitting for a number of hours is highly susceptible to problems like salmonella, he describes how Buttimer eliminate ‘dead-zones’, for example by inserting curved plates at the end of conveyors to prevent any build-up of product, and by carefully designing transfer points in the system to ensure efficient throughput, without areas where it can become lodged and collect.
SOLVING STICKY STORAGE
Storage of soybean meal can also present difficulties. The product has a tendency to compact and solidify when left motionless for an extended period of time, for example in a silo. “Even after a few days or a week it can go like a rock!” explains Olejniczak. For this reason, extra thought must be put into storage facilities, maintenance and product handling, even when its not required for processing or transfer. While Buttimer can design and install both silos and flat storage facilities for soybean meal, the preference is usually for flat storage solutions, where it’s easier to unload and, store and out-load the product, as it can be handled with a front-end-loader rather than relying on gravity to discharge a silo where the product is prone to bridging and compaction. Where a client has a preference for silos, a system for routinely transferring the product between silos needs to be implemented, with careful operation of HydroScrew discharge systems fitted with load sensors, discharging from the whole cross-section of the bin, maximizing the force of gravity towards the discharge, and taken mechanically out through the opening — if the product becomes compacted above the bin’s discharge screw it is almost impossible to get it out!
The lower density of soybean meal compared to other grains, as well as its ‘stickiness’, usually mean that soybean meal handling facilities have a lower throughput capacity for similar design, than a wheat, barley or rice facility would; therefore where a very high tonnage throughput per hour is necessary, higher capacity equipment and higher energy usage will likely be incorporated into the process design. Buttimer often recommends that its clients operate conveyors, chain conveyors and bucket elevators at as low a speed as feasible when handling soybean meal, as it is a relatively abrasive grain product there is a significant amount of wear and tear on equipment and the handling system, especially when processing at high speeds.
Buttimer has also developed the capability to load product to trucks and train wagons, often incorporating special dust-free outloading stations with aspiration bellows. Each intermodal port or inland terminal will have different logistics arrangements and outloading schedules, Buttimer’s process design integrates the material handling system with the broader logistics infrastructure and requirements.
In order to maximize the clients’ return on the capital investment in a handling and storage facility, equipment lifecycle management, a well-designed and adhered to maintenance programme and well trained, informed operators are crucial, Buttimer insists. “If the first step to designing a bulk material handling system is understanding the characteristics of the bulk product,” proposes the Group’s director, Fergal Buttimer, “then the next step is understanding the business requirements of our client.” Buttimer focuses on keeping the ‘Total Cost of Ownership (TCO)’ matrix low by building sustainable handling systems, ensuring that its mechanical systems are designed to be durable, efficient and ultimately, meet the clients’ long-term requirements. Incorporating equipment lifecycle optimization into the design and installation phase can save significant amounts of stress, maintenance and repair expenditure after the system has begun operating; for this reason, Buttimer is always keen to work with the final operator from early in the design process.
Equipment lifecycle management includes a knowledgeably designed and stocked spare parts store, with appropriate motors and gear replacement parts — the goal is to keep the parts store small, but reaction times very quick.
BUILDING ON BULK KNOWLEDGE
Buttimer has completed a number of large soybean meal handling facilities, building up experience and expertise in what they see as a potentially high-growth area of their business. A large project at the port of Swinoujscie in northern Poland has a handling and storage capacity for 50,000 tonnes of soybean meal, with ship unloading at a rate of 800tph (tonnes per hour) and out-loading capability to ship, trucks and rail transport networks. The facility was designed for Bunge, one of the world’s largest traders in oilseeds and edible oils, and was completed in 2012. The facility, which is engineered using specialist grain handling equipment manufactured by Cimbria, includes many of the process engineering features specific to soybean meal described above; it also has rapeseed cake handling capabilities, another component of Buttimer’s bulk knowledge. This summer Buttimer has begun designing a port facility for Morski Terminal Masowy Gdynia (MTMG) — part of the large, French ATIC logistics group. The soybean meal handling facility at the Port of Gdynia will unload Panamax-size vessels at a rate of 1,200tph and include a large flat storage facility with transport throughout the store via belt conveyors, chain conveyors, bucket elevators and pneumatic slides.
With the growth in production of biodiesel from soy in the US and elsewhere, and steady growth in demand for soybean meal in Eastern markets, soybean and its derivative products look set to be a significant portion of bulk cargo trade for the foreseeable future. Buttimer has built up expertise and experience in handling soybean meal in much the same way as it has with other products such as rice, wheat, barley, ores, minerals, coal, wood-chip and others. The potential growth in the oilseeds market, and global trade in soybean meal in particular, Buttimer hopes, will put its consultancy, design and project management skills in demand, and can give it a competitive advantage and open new opportunities in international markets.