Skip to main content

Handling hurdles

Published by
Dry Bulk,


Developing countries around the world often place a large amount of emphasis on the import and efficient use of fertilizers, and often provide subsidies to importers of the commodity in an attempt to promote self-sufficiency in agri-products by increasing crop yield. However, it is evident that, at times, money may well be better spent in the development of the handling processes, which can often, if left unchecked, indirectly increase the cost of the product to the end-user. More often than not, this is a direct burden on the small holder farming for subsistence and thus defeats the intention of subsidisation.

In this article, the author looks at some of the challenges that arise when handling bulk fertilizer cargoes, particularly at discharge ports, and highlights some of the practical solutions that can be implemented to absolve the potentially high costs that can be incurred through malpractice by all stakeholders. The following topics are touched upon in this article as being contributing factors to the degree of success in handling fertilizers by terminal operators – particularly in developing countries where there may be limited infrastructure and handling equipment:

  • Nature of fertilizer handled and its characteristics.
  • Mode of shipping for the commodity and adequate controls during the sea passage.
  • The main areas of concern when handling bulk fertilizers at discharge ports.
  • Solutions and techniques available to deal with problems.
  • Potential benefits to the end-user.

The Nectar Group manages several bulk ports in Africa and the Far East and operates a range of handling equipment in ports across the world, with a specific focus on handling dry bulk products, such as fertilizers. The group has handled millions of tonnes of bulk fertilizers in developing countries over the last 45 years.


Figure 1. Discharging hardened fertilizer from a vessel’s hold is challenging and costly.

Characteristics of fertilizer handling

The most commonly handled fertilizers shipped in bulk to markets around the world include urea, DAP, NPK, MOP and MAP. Typically they all show hydroscopic tendencies that can create ‘damp’ product; however it is possible for the suppliers to add anti-caking agents to reduce the effect that moisture has on the material. Some fertilizers are more prone to ‘lumping’ than others, such as DAP, which will require additional handling techniques. The humidity of the tropics mixed with fluctuating day and night time temperatures can be a great recipe to create, quite literally, rock solid fertilizers.


Figure 2. Handling of moist or lumpy cargo affects the entire chain.

From a terminal operator’s point of view, the timely discharge of the vessels without incurring demurrage costs or cargo degradation and shrinkage during the discharge is an important consideration. However the discharge operation of such cargoes is just one element of the logistics cycle that stretches from the supplier to the shipper to the receiver/end-user. The problems that a terminal operator experiences at the point of discharge could potentially emanate from shortcomings throughout the treatment of fertilizers along the logistics chain before reaching the port of discharge. These oversights can lead to the deterioration of cargo quality and/or cargo losses, which presents a variety of problems for all the parties involved in the logistics chain and, not least, for the receiver who expects to receive the goods in a certain condition.

Shipping logistics

For a terminal operator handling fertilizers in a developing country where remedial resources and handling equipment can be limited or not available, discharge operations can prove to be very costly.

There are three key stages in the logistics cycle of handling fertilizers from shipper to end-user, where careful consideration is the key to maintaining integrity of the cargo throughout. These are: the preparation and shipping of the cargo; the handling of the cargo at the discharge port; and the direct or indirect delivery to the end-user from the port.

At the first stage, the shipper has a responsibility to ensure that the physical characteristics of the cargo offered at the loading facility from the plant is exactly what is contracted. Any processes that assist the fertilizer to maintain its free-flowing properties, such as prilling of urea cargoes, need to be carried out carefully before shipping. The quality of the process, as well as proper inspection and validation of the process before approval of the cargo for loading, are important steps to maintain quality.


Figure 3. Handling methods need to adapt to the issues.

The hydroscopic property of many types of fertilizers is inherent in nature and, in order to minimise the detrimental effect of such properties, cargo temperature and atmospheric conditions at the load port need to be carefully monitored during the loading process and before closing the vessel’s hatches so no problematic conditions are created upon arrival at the discharge port. When the fertilizer continues to draw in moisture as it cools down and loses its free-flowing properties, it becomes very difficult to handle. Care should be taken to interrupt loading operation when critical tolerance levels are reached to minimise costly remedial action further down the chain.

It is equally important for shippers to provide the master of the ship with a detailed cargo datasheet as well as specific instructions as to the care of the cargo during the sea voyage. The specific instructions related to the ventilation and temperature control during the sea voyage and taking into consideration the different climate conditions between the load and discharge ports is crucial. The ship should not only carry out such instructions but record parameters on a daily basis throughout the voyage.

Areas of concern and solutions

The condition of the fertilizer on board the vessel upon arrival at the discharge port will significantly affect the quality and speed of discharge operation. For cargoes that retain their free-flowing properties, it is important to ensure that the weather conditions are monitored carefully during the discharge operation, especially during the rainy season, at discharge ports. Timely opening and closing of hatches in order to minimise moisture absorption is important during the discharge.

It is important for the terminal operator to have access to trained manpower and correct handling equipment in order to ensure the optimum discharge speed is achieved, which is crucial in most circumstances for the product to reach the end-user in a timely fashion – and it is in this area that investment is often lacking. For example, suitable mechanical trimming equipment is required, often early on in the discharge, to ensure that there is enough constantly free-flowing bulk product in the hatches for the grabs to collect. This is why, from the start of the operation, it is absolutely imperative that the stevedores try and work the hatches evenly during the discharge operation, making sure that cargo is not taken by the grabs solely from the area in the middle of the hatch. It may seem easier and quicker but it can create walling of the commodity along the bulkheads of the vessel if the product is not completely free flowing. With regards to the cost implication, this is cumulatively the most costly mistake seen in the discharge of fertilizers.

If the fertilizer has lost its free-flowing properties upon arrival at the port of discharge where cargo handling facilities and equipment are limited, the discharge operation could potentially become a protracted affair causing major problems for the participants, including the terminal operator and to all stakeholders in the chain. It is therefore important to employ external surveyors to observe, test and record any degradation of the cargo. Independent surveyors, which are available in every country, should be backed up by equipment, such as properly calibrated weighbridges, to protect the interests of both the supplier/shipper and the receiver. There is often evidence of trucks being overloaded with the tally not reflecting this, which then results in a short landing claim by the receiver. Alternatively, the receiver may not receive the contracted amount if the bagging equipment is over-weighing the cargo with each ’50 kg’ bag having an actual weight of 49 kg. In a 15 000 t shipment, this could equal a loss of 300 t to the receiver when the bags are each 1 kg underweight. It is therefore important to use an accountable bagging supplier that provides weight guarantees.

The type of equipment used, from grabs through to conveyors through to hoppers, also plays a large role in efficiency. Put simply, it is important that the equipment is suitable for the job. Many types of fertilizers are highly corrosive to handling equipment, therefore use of high-grade stainless steel for surfaces that make contact with the fertilizer increases the lifespan of handling equipment and assists in maintaining high performance levels during the discharge operation of fertilizers and ultimately reduces overheads in the long run. For example, a mobile bagging machine that has weighing systems made from mild steel will quickly slow and the weight accuracy will deteriorate due to corrosion of the intricate parts. While mild steel is a cheaper material to buy, it is more costly in the long run.

It may still be necessary to crush lumps of fertilizers on top of the bulk cargo hoppers in order to maintain cargo flow even after using mechanical trimming equipment in the holds. Such practice not only affects the speed of the discharge operation significantly but is also undesirable as having personnel on top of the hoppers during the discharge operation is not a safe practice. Safety is, of course, the highest priority to any operator and achieving international best practices in HSE can be problematic in the developing world and much time and effort has to be allocated to ensuring that strict adherence to safety policy is maintained to protect all involved.

If the fertilizer is directly bagged after passing through the bulk hoppers, non free-flowing cargoes will also affect the weight accuracy of the bags produced outside of the normal parameters of +/- 0.5% on average. Receivers rely on delivering accurately weighed, good-quality fertilizers to end-users, therefore it could be negatively affected as a result of the problems mentioned.

Finally, if the cargo is delivered indirectly, it is important that the storage facilities that are used have the adequate protection from the elements and possible contaminates and standards of trucks are monitored to maintain the quality of the bulk or bagged cargo. Essentially, the alignment of all parties in the chain, while not always possible or practical, remains the best protection against lengthy and costly operations. The transfer of information from the supplier to the vessel’s master to the onward parties is of utmost importance and can mean the difference between a success and a failure in promoting increased crop yields in developing countries where food can often be in short supply.

 

Author

 

James Luther, Nectar Group.

 

Note

 

This article first appeared in World Fertilizer's November issue. To read this and much more, register to receive a copy here.

Read the article online at: https://www.drybulkmagazine.com/special-reports/02012017/handling-hurdles/


 

Embed article link: (copy the HTML code below):