YANMAR Technical Review

Abstract

Yanmar developed a solution to decarbonize farm activities, its name is Farm Circular Solution (FCS). The solution turns the agri waste of a farm into valuable product for the same farm, in a circular and sustainable approach.
The circularity is achieved by optimizing and coordinating all tasks, from the pruning waste management in the field (Upstream) to the conversion into useful products (Gasification) and the use of the products in the farm and farm fields (Downstream). Contemporary disposal of waste and use of carbon negative products make farmers to achieve both economic and environmental sustainability.
FCS can strengthen Yanmar business and sustainable goals, also because the waste flexibility allows the use of other type of waste (i.e. urban or other type of green waste) considerably expanding the market base of customers.

1. Introduction

Yanmar has elaborated a solution for solving energy and waste problems of farmers, the name is Farm Circular Solution (FCS). The solution aims at decarbonizing farmer activities by offering them the benefits of a circular and sustainable approach to agriculture.
FCS can be divided in 3 main tasks as depicted in Fig. 1: the fuel supply (UPSTREAM), the fuel conversion (GASIFICATION) and the output use in agriculture (DOWNSTREAM). Being all those 3 tasks completely carried out inside the farm, the farms installing FCS highly increases circularity and thus sustainability of their business. A video can be found at this link with insights including interview to researchers and farmers.

2. Customer description

FARM TYPE: FCS addresses any type of farm that cultivate permanent crops (vine grape, olive tree, other fruit trees etc). The ideal farm is medium/large, but also small farms associated in consortia or other communities can be a good trial.
FARM PAIN POINT: The cultivation of this type of tree needs a yearly cutting of branches to improve both quantity and quality of fruits. The cut branches (prunings) must be usually removed from the field since they can create hazards to the crop like fungi or bacteria. The removal is often costly for farmers and furthermore the cheapest way of removal (open field burning of prunings) is being limited or completely forbidden by local authorities, because of fire propagation risks and direct pollution from emissions.
FARM BENEFITS AFTER FCS INSTALLATION: FCS is an energy converting solution that needs biomass fuel to be operated. When the biomass fuel utilized is the prunings inside farm, the paint point of above is completely and cheaply solved. Furthermore, as for products described in Fig. 1, all the output of FCS can be utilized in the farm, consistently decreasing farm expenditures. Following are the 4 outputs:

• Heat: around 40kWth in form of hot water are continuously produced during operation. This heat can be used for any type of demand inside farm or can be used to dry additional prunings and produce surplus AgriPellet¹ for farm fuel purposes.

• 1AgriPellet is pellet made by zero km waste like prunings inside farm

• Power: around 20kWe are continuously produced during operation, they can be fed into the grid (giving farmers access to different type of incentives) or directly used inside farm (including battery charging)
• Biochar: Prunings are thermochemically processed inside gasification reactor and then discharged as a carbonaceous material that, if compliant to specific technical standards, can be defined as Biochar. Biochar can be put into the farm agricultural field, because it has crop improvement qualities. Furthermore, since the carbon of biochar that is put into the farm soil is carbon sequestered from atmosphere, the farmer access to carbon credits that can be traded in a specific market.
• Bio Wood distillate: The thermochemical processing volatizes some compound of prunings that, once condensed, create what is called Bio Wood Distillate (or Wood Vinegar). This liquid with high phenolic compound concentration shows qualities of crop improvements or pest control once sprayed into the field. The farmer can save money by decreasing conventional products for crop management, as well as can increase the sustainability of farm activity since Bio Wood Distillate is GHG free product.

3. Solution description

THE UPSTREAM PHASE: To supply fuel to FCS, it is needed to manage the pruning from the field to the gasification system, this task is defined as Upstream. FCS includes machinery and guidelines for farmers to optimize the upstream phase.
A pruning collector takes pruning from the ground and compacts them into micro bales. Bales are then moved out of the agricultural field for storage and drying purposed and finally mobilized to the gasification system. The baler implement has been chosen for easy and cheap pruning management, and especially because it allows the free drying of micro bales during storage (solar and wind decrease the moisture content of bales). (Fig. 2):

THE GASIFICATION PHASE: As for in Fig. 1 the gasification phase is composed by 2 separate systems; both are containerized to reduce cost of delivery as well as the installation cost (no civil works or other infrastructures need).
Container #1 (Fig. 3) is the pelletizing container, the micro bales once dried are loaded into this container to convert bales into a shape and size fit for the gasification container (AgriPellet). The choice of a specific and standardized shape of fuel input has been decided to minimize the risk related to solid fuel flow and thermochemical conversion troubles, this leads to a higher system reliability without sacrificing fuel flexibility.

In fact, one important feature of container #1 is that it can accept other than micro-bales pruning biomass. It has been specifically designed to process also loose biomass waste material of any kind (wood logs, straws, branches etc.). This will be highlighted in the conclusion ,when we will address a possible market base enlargement of FCS.
Container #2 (Fig. 4) is the gasifier system container, where the thermochemical conversion of solid biomass into valuable products takes place. It is the core technology of Yanmar FCS, specifically designed and patented for farm waste biomass during joint R&D activities between Yanmar and European Universities and other Research centers.

The first stage of the pelletization and gasification flow scheme in Fig. 5 represents the thermochemical conversion of the solid fuel: here a mass flowrate of about 20 kg/h of AgriPellet is converted into a gas (named producer gas) and biochar. The second stage is the filtering and conditioning of the producer gas. During this stage the gas must be cleaned, moisture must be removed and at last it must be cooled to allow its utilization as a fuel for the engine. To complete these steps, the gas flows from a cyclone into a dual stage catalytic filter (patented by Yanmar), to convert troublesome organic compounds (tars) into valuable permanent gas. During this latter stage, the moisture contained into the gas condenses together with a group of soluble organic compounds generating Bio Wood Distillate.

The last stage sees the combustion of the producer gas into a 4TNV98 Yanmar engine, modified accordingly to manage producer gas. A 25 KVA generator is directly coupled with the crankshaft allowing the production of electricity. The overall electric efficiency is around 20%.

THE DOWNSTREAM PHASE: This is the phase where the FCS output described in paragraph 2 are utilized in the farm. It is important to note that all output can be used directly in the same farm that produced pruning waste (complete circularity). 2 out of 4 outputs can be used for servicing the farm activities (heat and power), while the other 2 can be used directly in the field to improve the main farm crop, these are Bio Wood Distillate and Biochar.
As for Biochar, it is more than 10 years now that positive effects on soil and crops have been scientifically demonstrated, such as water retention into soil (the porous matrix of biochar can retain water during rainy seasons and release it during dry ones) and reduce nutrients leaching (i.e. N and P are easily sorbed by biochar). The first effect is considered of capital importance for a future environment where climate change will exacerbate rainy and draught seasons.

As for Bio Wood Distillate, it can be used as organic product for several purposes like to stimulate vegetable growth, repel crop insects, and boost crop resistance to adverse abiotic conditions. Yanmar FCS includes suggestions to farmers about specific uses and methods (application guidelines) of biochar and Bio Wood Distillate produced from the gasification system installed in their own farms.

FCS SUPERIOR POINT TO COMPETITORS: while other company commercialize gasifier, all of them focus on technology only, externalizing to customer or even completely not including the task of fuel supply (Upstream) and use of output (Downstream) in the farm. On the contrary, an energy generation process that use fuel originated inside farm and utilize the carbon negative products of the same process inside the same farm, is not yet visible on the market. Table 1 resume FCS uniqueness compared to state of art.

Table 1: Superiors points of FCS in respect to competitors

4. Conclusions

FCS idea and targeted market sector can strengthen Yanmar business and sustainable goals. From customer point of view, FCS will be the occasion for farmers to match environmental sustainability (carbon negative products) and economic sustainability (cost negative fuel, since it is fuel coming from farm waste).
Furthermore, as mentioned before in paragraph 3, the technical solution allows waste flexibility, that means that other type of waste (i.e. urban green waste, golf course waste etc.) can be processed by FCS, considerably expanding the market base of customers (i.e. City Circular Solution, Golf Clubs Circular Solution etc.)