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Executive Team

Greenbelt Resources – Executive Team

Darren Eng
Chief Executive Officer & President

Darren Eng is Chief Executive Officer and President of Greenbelt Resources Corporation. Prior to his appointment to CEO, Eng served as a Board Director starting in December 2008, and performed the role of Secretary for the Board from April 2009 to September 2009.

Eng has over 20 years of experience in executive leadership roles and entrepreneurial endeavors. As founder and President of The Sponsorship Group, he has been titled Executive Director or Senior Vice President of a number of professional organizations operated and managed by The Sponsorship Group staff. Other past senior management positions include Operational Director of Los Angeles Venture Association and Executive Vice President of the Digital Evolution Center. Prior to running various upstart companies and organizations throughout Southern California, Eng worked for nearly a decade in the environmental industry. From 1994 to 1998, he led teams of scientists and engineers at AECOM (formerly ENSR) as a project and team manager and served as a level III associate scientist. His work included regulatory compliance and liability assessments of Southern Natural Gas facilities and other large bank-financed industrial properties in the eastern U.S. from Maine to Louisiana.

Eng earned a Bachelor of Science degree in biology (environmental tract) from Yale University in New Haven, Connecticut. Eng is Chairperson of the GreenLAVA SIG for He is also a current member of both the Men’s Guild for Children’s Hospital Los Angeles and the Yale Science and Engineering Association.

Joseph Pivinski
Chief Financial Officer

Joe Pivinski possesses broad financial management expertise and exposure to a diverse range of industry sectors over a 35+ year career, including consulting, construction, manufacturing and staffing and engineering services. He has served in leadership positions in public companies as Senior Vice President and CFO of Consolidated Water Co., Ltd., Vice President – Finance and CFO of Oriole Homes Corp. and CFO of the U.S. subsidiary of Adecco, S.A.

In addition, Pivinski has held C-level and board positions with other public and private organizations, from development stage to $1.0B in revenues, often with direct responsibility for multiple business functions – including HR, facilities, IR and IT. He has significant experience in regulatory reporting and compliance and accomplishments with international and U.S. capital market transactions and acquisition integration.

Pivinski holds an MBA – Finance from Fordham University in New York and is a CPA. He is a member of Financial Executives International.

Floyd Butterfield
Chief Technology Innovator and Treasurer/Secretary

Floyd S. Butterfield has served as company Secretary since November 2010, Treasurer since October 2008 and as a Director of the company since April 2007. He is also the Chief Technology Innovator of Diversified Ethanol Corporation, a wholly-owned subsidiary of Greenbelt Resources.

Butterfield has over 25+ years of experience in the biofuels industry and is the designer of the Butterfield Closed Cycle System™ ethanol plant. With his vast experience in ethanol production from a wide variety of conventional and alternative feedstocks, Butterfield’s innovative approach to alternative fuel production earned him the top award from the California Department of Food & Agriculture and the California Waste Management’s Fuel Alcohol Plant Design Competition in the early 1980’s.

Butterfield serves as Director of Engineering and Manufacturing for Diversified Ethanol. Previously, he founded FSB Energy, a provider of design, construction and operational consulting services to the biofuel and geothermal industries. Butterfield also founded and served as COO of Curbside Container Company, where he developed six patents related to recycling containers. He also served as CEO of FSB Farming, founded in 1983, a diversified farming operation and grower of carrots and tomatoes for large packing operations.

Butterfield holds a Bachelor of Arts degree in geophysics from Occidental College and attended the Colorado School of Mines Geophysics master’s degree program.

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