Green, Yellow, and Woody Biomass Supply-Chain Management: History Edit
Subjects: Energy & Fuels

For the generation of any product, a sequence of processes connected to design, decision making, and execution, and a series of financial, information, and material flows are performed throughout different stages of the production. The different stages of the production constitute an integrated system called supply chain. The basic aim for the successful design of a supply chain is to meet the requirements of the final customer regarding a specific product. The supply-chain concept for agri-food and biomass relates to not only manufacturing and retailing sectors but also to agricultural sector.

In recent decades, energy crops constitute a highly-potential share among crops taking into account the need for greener energy production. Energy crops are crops that are cultivated for biomass, biogas, or other biofuels (e.g., biodiesel, bioethanol) production. They are mostly green crops that come from wild nature, such as perennial grasses with high potential for bioenergy production. Green-type biomass includes crops such as Miscanthus, Panicum virgatum (also known as switchgrass), Arundo donax, etc. At the same level, yellow biomass refers to crop residues that come from any crop and represent another category of biomass production related to feedstock. Examples of yellow biomass are corn stover, wheat straw, etc. It should be mentioned that the main sources of biogas production are the energy crops and the use of agricultural residues [1]. On top of this, there is a variety of woody crops that contribute significantly to biomass energy production globally. Woody biomass is any biomass that is connected to wood sources. Examples of woody biomass sources are willow, poplar short-rotation coppice, etc. All of them have various and complex constraints regarding the entire management policy and practices that should be followed for the optimal biomass production.

The main challenges regarding supply chain issues on each biomass type category, as they are presented above, are different. Challenges related to green-type biomass include any grass-type crop operational issues, including particular issues in harvesting and handling (such as optimal scheduling), and less on other processes (such as soil cultivation or fertilization) due to their easy adaptability to various environments. On the other hand, yellow-type biomass requirements include optimal collection, handling and transportation processes. This incorporates on-time scheduling of collection and transportation and optimal task execution in cases where multiple fields are covered. Challenges on woody biomass sources are different from the other two types given its operational processes particularities. The woody energy crops require different crop establishment, cultivation, harvesting, and transportation processes. Of course, some operational issues would be similar with the other two types (such as scheduling of operations), but there are technical issues that are solved in different ways. A short example regarding collection and transportation would be about harvesting of green or yellow biomass in bale form compared with woody crops that whole trees are collected.

At this time, supply-chain management (SCM) in agricultural production, handling, and transportation processes is vital and there are always various issues that should be faced through better SCM. There is a large amount of research works regarding SCM of green, yellow, and woody biomasses. The work here, targets on an up-to-date literature review on recent publications on green, yellow, and woody biomass SCM.

The main challenges for the creation of this review were, firstly, to underline variation practically in different approaches for specific existing problems in SCM, secondly, to provoke the development of supply-chain management on the specific target group by proposing possible solutions on various upcoming matters and, finally, to provide a brief review of various followed practices/methodologies and their effects on the SCM.

There are previous reviews on the supply-chain management in agricultural processes regarding green, yellow, and woody biomass types. A biomass supply chain evaluation and optimization are suggested by a literature review regarding forest feedstock [2]. A systematic review was presented in order to present the key factors throughout the biomass supply chain of green and woody crops that affect the application of bioenergy buffers in complex bioenergy production systems [3]. A wider review about biofuel SCM is conducted under the objective of uncertainties and sustainability issues [4]. On the opposite side, a more practical review was presented regarding many types of mathematical models in bioenergy crops production, including both energy crops production processes and transportation but also biorefinery/biomass conversion modeling processes [5]. Even though the scientific contribution of these reviews is highly important, to the knowledge of the authors, there is no recent review regarding chain management aspects for green, yellow, and woody supply.

The objective of this paper is to highlight and focus on green, yellow, and woody biomass supply-chain management research works (52 studies), and, as a second step, to create a classification in order to propose opportunities for further research by focusing on research gaps and identified issues needed to be tackled.

Supply-Chain Management Definition

In order to conclude to a successful definition of SCM, i is important to make a short comparison between traditional management (TM) practices and SCM practices. Under the financial concept, by TM a reduction in a company’s costs may be achieved, while by SCM a whole-chain cost efficacy will be obtained. Regarding data exchange and monitoring information, the first case is limited on the business’s own needs, while in SCM it can be extended for whole-chain planning and/or monitoring processes. Another point is the coordination between different levels of a channel, where in TM there is only a single contact for the interchange among the channel pairs, while by SCM multiple contacts and coordination between various businesses and levels of channels can be accomplished. Finally, there is a number of risks and rewards that cannot be shared under the TM philosophy, but by SCM all the risks and rewards are shared in a long-term period. The above-mentioned comparison is only a small sample of the differences between TM and SCM, suggesting the need for assimilating more and more SCM practices.

There are various ways to describe and define SCM. For the purpose of this paper a definition of the term regarding crop production processes would be: Supply-chain management is the integrated planning of in-field and/or logistics operations, application of these operations, coordination between the different levels of the channel(s) and, finally, control of all processes and necessary activities in order to produce and transport, in the most efficient way, the products that finally will satisfy the requirements of a given market [6].

Given this definition, we could set that all the in-field and logistics processes are included in the term supply chain, not only as a physical operation but also as a decision-making activity, both associated by material flows and exchange data and, as a consequence, the correlated financial/energy flows. In this light, the supply chain includes not only the producer and its suppliers, but also includes the processing units, logistics operators, warehouses, etc.