Circular Economy of Green Gold: From Oils to Biofuels

Circular Economy of Green Gold: From Oils to Biofuels

Green Gold International is the first Bulgarian company to close the cycle on all by-products related to wine-making. In the spirit of the circular economy and green technologies, we have developed and introduced a fully integrated production process. Our innovative approach transforms waste residues generated by vineyards and wineries into two distinct value-added products – cold-pressed grape seed oil and high-quality biopellets.

The project started in late 2018 as a pilot study in grape seed oil production but gradually evolved into a more wholesome manufacturing endeavor. The company’s founder initially had an interest in grape pomace (also known as marc) which is a by-product of wine making – crushed grapes being expelled as wet to semi-liquid mass from wine fermentation tanks at various stages of wine maturation. Usually the pomace is mostly disposed of as waste, sometimes fed to cows and pigs as fodder.

The pomace is rich in grape seeds which in turn hold the healthy and multi-purpose grape seed oil. With a view to preserve all its natural properties, Green Gold Int. started off trying to produce cold-pressed extra virgin (unrefined) grape seed oil. To this end we found technologies to process the input (grape pomace) – clean, separate, dry, store, and then press the seeds at optimal conditions. The company’s first successful attempt at producing premium cold-pressed grape seed oil arrived in 2021.

Next, we decided to dig deeper, aiming to put to use the other component of grape marc – the grape skins. For this purpose, we built a small biopellet line and devised a novel recipe with timber and grape skins that yields a high-quality biopellet. So far so good. 100% waste-free utilization of wine-making by-products. Only wine-making by-products are not just found in wineries.

Apropos, after speaking to a few of our winery partners in the late summer of 2022 we learnt that vineyards also produce “waste”. During winter and beginning of spring, vineyards are subjected to cutting of shoots – the branches that will no longer produce good grape and are to be naturally replaced by newly-born shoots from the vine. Interestingly, vineyards consider the disposal of shoots a nuisance and generally burn them in the field in large piles.

However, these shoots represent a type of fruit timber that can serve as biofuel. So we arranged that cut-off shoots be delivered to our facilities. After upgrading and refashioning our biopellet line we managed to add vine shoots as an alternative source of timber to our biofuel recipe, and still preserve the quality of biopellet.

Thus, after 4 years of research and experimentation, investment and innovation, we can humbly say that we have seen some materialization of our efforts. Our results are three-fold. Firstly, we have managed to developed a new technological approach in green manufacturing, not so much in terms of engineering but rather in its circular-economy approach to a whole segment of an adjacent industry – wine-making. Secondly, we have succeeded in producing (albeit still at a small scale) two high-value-added products starting from inputs with virtually zero economic value. Thirdly, in our attempts to integrate as many by-products of wine-making as possible, we have helped the latter industry in its handling of what they consider “waste” products.

What’s next for Green Gold Int. as 2022 nears its end? We have two main objectives – establish and expand. The former involves spreading the company name and products in domestic and local supply chains and getting a grip on markets. The second relates to upgrading the production facilities to a larger industrial scale. To this end, we commence actively searching for funding that could help us achieve these goals.

Contact us today to learn more about our technology, our portfolio, and our upcoming projects.